1. Field of the Invention
This invention refers to a process for wrapping loads, in particular palletised loads, and to a system for implementing the method.
2. Description of the Related Art
As is common knowledge, palletised loads consist of one or more goods distributed in a more or less orderly manner on a pallet so it can be moved and transported in a practical and easy way.
The palletised loads are normally covered with a stabilising wrap that immobilises the loads on the pallet so the loads can then be transported without any risk of falling or tipping over.
The usual way to make such stabilizing covering is to tightly wrap the sides of the load and pallet with a plastic covering film that is unwound from a dispensing reel.
Wrapping is normally done by means of either automatic or semi automatic wrapping stations, which use one or more machines, intended to move a wrapping head which supports the reel of plastic film.
In a particular type of wrapping station, the movement machine is made of a rotating frame that, to wrap the covering sheet on the load to be wrapped, supports the wrapping head, driving it with a lifting and rotating motion around the palletised load which remains substantially still on the supporting stand.
In another type of wrapping station, the movement machine consists of a vertical post along which the wrapping head slides while the palletised load turns on a rotating platform.
Both the supporting stand and the rotating platform of these two types of wrapping stations have a system for advancing the palletised load, e.g. a motorised roller unit, a chain conveyor or a mechanism type, that allows the palletised load to be transported along an automated movement line, stopping the load near the movement machine so it can be wrapped.
In both types, moreover, the reel is mounted on the wrapping head in a way that it rotates around its own axis and, during wrapping, is kept substantially vertical and parallel to the sides of the load.
Hence during wrapping the palletised load is wrapped with several spiral windings to achieve a particularly strong stabilising wrap.
At the end of wrapping, the plastic film is cut with a cutting device on the wrapping head and the end thus cut is sealed on the palletised load by a heat sealing pad.
The heat sealing pad is also mounted on the wrapping head which, in turn, is mounted on horizontal guides so it can be moved near to and away from the palletised load.
In both types of wrapping stations mentioned here, after the plastic film has been wrapped around the palletised load, the wrapping head moves up to the load, cuts the plastic film and seals the end thus formed making it integral with the stabilising wrap that is wrapping the palletised load.
Such wrapping stations do, however, have some drawbacks, among which is the fact that they are rather complex and complicated from both a structural and functional point of view.
In this regard, the fact is emphasized that the need for movement means on the wrapping head to move it near to and away from the palletised, load entails some considerable difficulties and complications, both during the assembly phase and when the wrapping stations are working, leading to a notable increase in manufacturing, installation and maintenance costs.